Thank you so much for the tips so far! They've been extremely helpful.
So I bought a set of silk plants that are nice and tall with broad leaves and a new live plant that's larger and put those in. Also acquired a check valve for my filter, and a 1" airstone to replace the larger one that I wasn't so fond of.
The heater came today and the water is coming up. It's the Hydor slim heater; I hid it under the gravel. The testing strips came too, and I discovered, lo and behold, that yes, my water is hard. Is there a way to treat the water currently in his tank for this or should I not worry too much about this for right now since I'm planning to use bottled water from here on out? I'm planning to do my first partial water change in his tank next Wednesday.
His tank after adding the new heater, air stone, and plants:
And Michael says hi: